[lldb] make lit use the same Python executable for building and testing

[charles-zablit]

When testing LLDB, we want to make sure to use the same Python as the one we used to build it.

This patch uses the CMake variable Python3_ROOT_DIR to add the correct Python to the PATH in LLDB lit tests, in order to ensure of this.

Please see swiftlang/swift#82063 for the original issue.

This is a continuation of swiftlang/swift#82063.

[llvmbot]

@llvm/pr-subscribers-lldb

Author: Charles Zablit (charles-zablit)

Changes

When testing LLDB, we want to make sure to use the same Python as the one we used to build it.

This patch uses the CMake variable Python3_ROOT_DIR to add the correct Python to the PATH in LLDB lit tests, in order to ensure of this.

Please see swiftlang/swift#82063 for the original issue.

This is a continuation of swiftlang/swift#82063.

---

Full diff: https://github.com/llvm/llvm-project/pull/143756.diff

2 Files Affected:

• (modified) lldb/test/Shell/lit.cfg.py (+3)
• (modified) lldb/test/Unit/lit.cfg.py (+3)

diff --git a/lldb/test/Shell/lit.cfg.py b/lldb/test/Shell/lit.cfg.py
index ab6113767187a..a48d43251c988 100644
--- a/lldb/test/Shell/lit.cfg.py
+++ b/lldb/test/Shell/lit.cfg.py
@@ -203,3 +203,6 @@ def calculate_arch_features(arch_string):
 # location of the Python libraries. This ensures that we use the same
 # version of Python that was used to build lldb to run our tests.
 config.environment["PYTHONHOME"] = config.python_root_dir
+config.environment["PATH"] = os.path.pathsep.join(
+    config.python_root_dir, config.environment.get("PATH", "")
+)
diff --git a/lldb/test/Unit/lit.cfg.py b/lldb/test/Unit/lit.cfg.py
index 681e3b19dce34..38ab821e5ee16 100644
--- a/lldb/test/Unit/lit.cfg.py
+++ b/lldb/test/Unit/lit.cfg.py
@@ -34,6 +34,9 @@
 )
 llvm_config.with_environment("PATH", os.path.dirname(sys.executable), append_path=True)
 config.environment["PYTHONHOME"] = config.python_root_dir
+config.environment["PATH"] = os.path.pathsep.join(
+    config.python_root_dir, config.environment.get("PATH", "")
+)
 
 # Enable sanitizer runtime flags.
 if config.llvm_use_sanitizer:

[JDevlieghere]

Makes sense for the shell test (we could also make it an alias and resolve the path ourselves, that would be a bit more reliable) but why is this necessary for the unit tests?

[labath]

+1 for %python

[charles-zablit]

On Windows, lldb looks for python39.dll when running the tests. Therefore, even if we make the path an alias, lldb will still not be able to resolve python39.dll if it's not in the PATH env variable.

but why is this necessary for the unit tests?

It is not, after testing it does not impact the tests. However, python39.dll being in the PATH does impact the API tests, as dotest will try to run lldb before starting the test suite. If the DLL is not in the path, the lldb -P invocation fails.

[JDevlieghere]

Thanks for explaining. LGTM.